Fire extinguisher



Sept. 26, 1944. J. c. CARTER FIRE EXTINGUISHER Filed Jan. 5, 1942Patented Sept. 26, 1944 UNITED? STATES PATENT OFFICE FIRE EXTINGUISHER IJoseph Coates Carter, Martinsville, Va.

. Application Januaryz5, 1942, Serial'No. 425,684

, 9 Claims.

This invention pertains to a fire extinguisher. that automaticallyreleases. gas to smother a flame.

It has been desirable to apply extinguishing sprays automatically. It isnot always desirable to arrange an. automatic extinguisher as part of amore or. less permanentstructure. Preferably, it is desirable to devisean, arrangement that can be used either in a permanent structure or ina, portable extinguisher. A purposein this invention;is,to provide thisadaptability readily. A need exists also for a simple arrangement of lparts to be replaced after use of thecxtingu'ishen. A feature of the,present invention is. to utilize elements that are of themselves wellknown and usually available, but that may permit interchange ofmaterials in the eventthat certain of the elements become unavailablefor one reason or another.

A generalpurpose of this invention is to pro.- vide extreme simplicityof manufacture, and also to provide dependable and automatic operationwhen need exists for the extinguisher. Other objects of this inventionwill appear in t-he.a.ccompanying description.

In the accompanying drawing are, shown: illustrative embodiments, whilethe accompanying claims particularly point out novel I features; of theinvention. The following description isillustrative of preferredpractice that. furthers the objects for which this invention is suited.

In the drawing: Figure 1 shows in elevation'part. of a wall; of theenvelope of the extinguisher Figure.2 shows a vertical section throughthe. extinguisher within the container shown in, ele-. vation in Figure1;

Figure 3 shows a horizontal cross section of the extinguisher takenalong the line 3--3. of Figure 2;

Figure 4 is a vertical section taken across, the extinguisher along theline 4-4 of Figure 2;

Figure 5 shows in horizontal cross section analogous to Figure 3 amodified form of structure embodying this invention; and

Figure 6 shows in vertical section analogous to Figure 4 a furthermodified structure embodying the featuresof this invention.

According to preferred practice the objects ofv this invention areattainable by arranging a plurality of thin walls within an envelope toform a cellular structure, some of the cells containing, reagent of onesort and the, other cells contain ing reagent of another sort such thatthe two when intermixed yield flame-extinguishing gas.

The arrangement is such that on slight elevation of temperature theseinterior walls or some of them will fuse and the reagents in adjacentcells become intermixed automatically within the envelope and generatesufiicient pressure for the gas to burst from the envelope. 7

Referring more particularly to the drawing illustrating specificpreferred embodiments of this invention, the envelope I is of thinheat-conducting material such as thin sheet metal. Suitable material,for example, is such as currently is used to form cans. -Within thisenvelope the be filled with acid and others may be filled with.

bicarbonate. These materials, however, are il-v lustrative and are notlimiting of this invention inasmuch as other materials suitable for thepurpose are known to those skilled in the art.

A suitable disposition of reagents in the cells will be an alternatearrangement of liquid as in cells 2' and next of a solid as in cell 3.The re: sulting pattern is tessellated, such as illustrated in Figure 2.This shows in vertical section a liquid filled cell 2, above a solidfilledv cell 3 and that in turn above a liquid filled cell 2. In an ad:joining column this arrangement is reversed so that the solid and liquidfilled cells alternate in horizontal as well as in vertical rows. Inthis way if the walls between contiguous cells become softenedsufiiciently to yield, there will be at once an intermingling of acidand of solid. In practice this yield point may be confined to a smallarea initially, but if the temperature continues to rise may spread overconsiderable area.- Thus if the area of rupture is slight the rate ofintermixing of acid with solid will be correspondingly low. Thus aninitial release of gas may be. slight, but if the flame or heat requiresa considerable release of gas then the rupture of walls will beconsiderable and the amount of gas formed will be correspondingly,great. I

The walls that fuse and weaken first may be those at the top and bottomof a cell or ma be illustrated in Figure 4. This heat flow willcorrespond to the demand,- that is to say, correspond to the intensityof flame to be subdued and to its disposition near the extinguisher. InFigure 4 is illustrated an extinguisher that is relativelynarrow, withside walls I of the envelope close together. Thus heat may betransmitted quickly from both side walls I to the fioor wall 5 of cell 2if the flame substantially surrounds this cell. On the other hand, if aflame is of such low in tensity as to heat one wall, but notsubstantially to heat the other wall, the temperature of the floor wall5 of the cell will rise primarily near the corner next to the flame.Thus in the first instance the whole floor 5 may weaken at once and acidmay intermix quickly with a considerable amount of solid. On the otherhand, where the weakening occurs only near one corner the passage ofacid will be confined chiefly to that corner which is already weakened.

When gas is formed in the envelope, necessarily pressure rises withinthe envelope because of the impervious nature of the walls I. Thispressure may be made effective in various ways.

In the form of this invention illustrated in Figure 4 of the drawing,means to utilize pressure developed within the envelope comprise fusibleplugs 6 as a part of the envelope wall I. These plugs may be composed ofmaterial that weakens under the influence of heat as by fusion. For thispurpose suitable materials will be known to those skilled in the art.Preferably such material for plugs 6 will weaken or fuse at atemperature somewhat higher than that of the cell Walls 5. This is sothat the cell walls may weaken first and generate a considerablepressure of gas before the release plugs 6 are caused to weaken. Withsuch arrangement the gas spurts out with considerable force and spreadsover considerable area at once. The bursting or blowing out of fusibleplug 6 will be facilitated by the growing gas pressure within thecorresponding cell. Thus with high heat and sudden generation ofrelatively large amount of gas, the plug will blow out very quickly.Preferably the retaining plugs 6 are disposed in alternate solidcontaining cells 3. The efiect of this disposition is to permitconsiderable pressure to be built up by the time the plug 5 breaks. Theplug nearest the demand is the first to release gas.

In modifications of this invention mechanical means to rupture the wallsthat separate a liquid cell 2 from a solid cell 3 may be provided. Suchmeans are illustrated in Figure 6 by a pull wire I attached to interiorcell wall 5. This arrangement is such that pull element 1 extends fromits place of attachment to cell wall 5 through the mass of solid in cell3 and through enveloping wall I to the exterior of the envelope. Thuselement 1 may be pulled manually to tear back the cell wall 5 to permitmingling of acid with solid. ,In Figure 6 is illustrated only a singlepull element 1, but it will be understood that such a disposition may bemultiplied to rupture an cell walls.

In Figure 6 is illustrated further an advantageous structure to permitbuilding up of pressure within a cell and then sudden release of the gastherein. This arrangement comprises an automatic pressure-operated valve'8 that is inserted in envelope wall 1. Such pressure release valves areknown of themselves and are of various types that may be selected bythose skilled in the art. Such pressure release valves 8 may be used inconjunction with fuse plugs 6 or may be used as alternative thereto.

A further modification that may be used with the Various forms ofpressure release plugs or valves concerns an alternative disposition ofthe liquid reagent in capsules. Such a modification is shown in Figure5. In Figure 5 is shown a series 7 of liquid filled capsules 9 spacedapart and surrounded by a solid reagent that is simply packed or filledinto the envelope I. In Figure 5 these capsules 9 are illustrated asbeing cylindrical, but it is understood that under this invention theseliquid filled capsules may be of any other shape. It will be understoodfurther that either the cells or capsules may be of any suitable shape,such as cylindrical or hexagonal, as may be preferred for the purposeand under-the requirements at hand.

It becomes evident from study of the advantages of this invention thatin many instances an envelope will be used only partially. This would bethe case where a small local fire weakens the walls of only a few cellsand where the'resulting gas pressure breaks only a few correspondingplugs 6 or else issues from only a few corresponding pressure releasevalves 8. Where" only part of the cells are opened, the remainingstructure is still usable and the parts already used may be replaced.

It will be observed further that an advantage of this invention residesin the possibility of replacing fusible plugs 6 in simple manner. Suchplugs may be of a nature to be fused or to be cemented quickly intotheir respective openings in the envelope wall I. As shown, plugs B areconvex to be snapped into place. Thus in'some instances repairs may bemade to a fire extinguisher on the spot where it has been in use whilein other instances repairs may be made readily to such extinguishers ashave to be removed to some equipped location.

It will be apparent that a structure of the sort described herein may beadapted to various purposes. For example, extinguishers of the formillustrated and generally of rather thin rectangular form can beinserted into a wall; or several such elements may be piled around asmall local fire and by their mere number and presence act as a bafileto exclude air from the burning material.

While I have in the above description disclosed what I believe to be a'preferred and practical embodiment of the invention, it will beunderstood to those skilled in the art that the specific details ofconstruction and arrangement of parts are subject to some latitude ofvariation without transcending the spirit and scope of the appendedclaims.

What I claim is:

1. A fire extinguisher comprising a cellular structure formed with thinwalls of heat-conducting material the cell units containing separatereagents adapted to interact on contact with each other to formfire-smothering gas within the envelope, the envelope walls beingadapted to rubture by heat and internal pressure and permit gasdeveloped therein to spurt from the ruptured portion.

2. A fire extinguisher comprising a, cellular 4. A fire extinguishercomprising a cellular structure formed with thin metal Walls tofacilitate rapid heating, some of the cell units therein containingliquid and adjacent cells containing solid reagents alternately forgenerating fireextinguishing gas on intermixture of the liquid with thesolid, the individual cell walls being fusible under heat to permitintermixture of the liquid with the solid.

5. A fire extinguisher comprising a cellular structure of thin metalwalls, the cells therein having interior walls of fusible material andbeing filled alternately with liquid and solid reagents, which reagentsgenerate gas under pressure when mixed, and fusible plugs in theexterior cell walls arranged to burst under heat and pressure ongeneration of gas within the extinguisher.

6. A fire extinguisher of narrow rectangular form comprising thin metalwalls of high heat conductivity, the interior walls being of lowtemperature fusible material providing a plurality of cells, said cellsbeing alternately filled with liquid and solid reagents for generatingflame-extinguishing gas on intermixture with each other.

'7. A fire extinguisher comprising an envelope filled with solid, andcapsules packed in the solid and containing reagent adapted to evolvefiresmothering gas when contacted with the solid, the capsule wallsbeing adapted to release their reagent on being heated, and the envelopewalls being adapted to rupture on the formation of gas, wherebyflame-smothering gas is spread over a flame.

8. A fire extinguisher comprising an envelope with interior cellularstructure, the cell units having low fusing wall portions and containingreagents to generate fire-smothering gas upon contact with each other,the envelope having spaced fusible portions adapted to be dislodgedunder the influence of temperature higher than that effective on theinterior structure, by gas pressure generated within the envelope.

9. A fire extinguisher comprising an envelope of heat conductingmaterials having ports with closures adapted to be blown out under thecombined influence of heat and gas pressure within the envelope, andreagents within the container separated by walls of fusible material,capable of combining upon the fusion of said walls to produce flameextinguishing gas under pressure within the envelope,

JOSEPH COATES CARTER.

